Here I would like to make another comment for the Well Tempered Clavier composed by my great friend Johann Sebastian Bach. This time is for 'the Fifteenth Fugue'. It is of course on G major.

The Calov Bible and the WTC cover

The Calov Bible is a commentary Bible written by Dr. Abraham Calov, a distinguished 17th century Lutheran theologian. Abraham Calov was the editor and commentator of the three-volume Bible. Each verse of Scripture was printed in large bold type followed by Calov's commentary in smaller, less bold type.
I happened to know that my friend studied the Calov Bible in earnest and I found out that in the lower right coner of the title page of each of the three volumes was the monogram J.S.Bach 1733 written in his own hand. He had been wanting to get for long and he could finally purchase these three volumes in 1733 through a local-leading bookdealer. In one place of the books, Bach wrote in, "In devotional music, God is always present with His grace." In another place, near the 25th chapter of I Chronicles, he wrote, "This chapter is the true foundation of all God-pleasing church music." He told that until then he had to read them at the church library. Of course he could not write anything nor add his comments on any page. He found the Calov Bible at first at the Lutheran Church of Saint Agnus when he was in Cöthen. He loved it. Especially he liked the cover of it. So he used its design image for the front cover of the Well Tempered Clavier.

eine Amusante

Even though Prince Leopold was basically "a prince who knew music as well as he loved it", in 1721 my friend's life in Cöthen had become less congenial after the prince's marriage on December 11th with a pleasure-loving girl at her age of 19 years old, whom my friend called "eine Amusante" according to the letter of the year 1730 to Mr. Georg Erdmann from Johann Sebastian. I saw the letter when I visited Dantzih in 1731. Her name was Frederica Henrietta von Anhalt-Bernburg. According to my inquiry through diplomatic channels, the situations were as following;
The wedding was followed by 5 weeks of festivities in the town and Johann Senastian provided two cantatas for the occasion. Prince Leopold was smitten by his new bride and he wanted to be always with her. She was attractive and pretty. She liked music. She brought a few of music scores as a part of her bridal belongings. Prince Leopold was over head and ear in love with her. He had gone to another pleasant place where my friend could not visit. But happy days would not last so long. Princess became to be in bad health about one year after. Then Prince looked after her day after day. He did not have time to enjoy music. Tragically, she died two years later, in the spring, on April 4th of 1723. Prince was stricken with her death and his mind was too occupied with her death to think about music and Johann Sebastian Bach. My friend felt deeply sorry for his Lord. On April 19th, he signed a curious document that reads as if he were not yet free from Cöthen, but he could be free within a month. He had already got appointment in Leipzig, so after several weeks he left with his family and their belongings for Leipzig on May 22nd of 1723.

Two of Bach's daughters were named after this Princess.
Christiane Sophie Henriette was born in 1723
and died in 1726 at three.
Elisabeth Juliane Friederike was born in 1726
and married with Mr. Johann Christov Altnikol,
one of the most eligible pupils of Johann Sebastian.

a part of Bach's letter to his friend Georg Erdmann of the year 1730eine Amusante or eine Amusa

As I said, in 1731 I saw the letter which had the phrase, "Princess might be eine Amusante". But now, in 1744, people were talking as if to say that Johann Sebastian Bach had named Princess as eine Amusa which is strained to "a - Muse = someone not interested in the Muses or a lady against the muses", "an anti-musical persona" or "unmusikalisch", in other words, "a person who hates music". It is believed that he wrote in the letter, "Princess might be eine Amusa". It is ridiculous. My Friend never wanted to insult a high personage like Princess this way. Actually Johann Sebastian told me that he did not know the word "Amusa" at all. Unfortunately Mr. Georg Erdmann passed away in 1736, so I can not ask him what happened. And I could not find the letter. I do not know where it is.

There are some doubts here.

Who knows the meaning of Amusa ?
Who falsified the word Amusante to Amusa ?
And why ?

Amusante is a French word, an adjective for the feminine. It means "pleasant". So eine Amusante means "a pleasant persona" or "a woman who makes people pleasant". In this case A of the adjective Amusante should be a capital letter according to the German grammar. So in the letter A was written big in script like in "amusante".

Amüsant is a German word which has the almost the same meaning of Amusante. ü is necesary here for German. But my friend did not use it. So this Amusante is a French word, intentionaly selected by him.

For Amusa, A is not necessary to be a capital letter. eine amusa should be the proper expression. "eine amusa" is strange. Moreover only some dilettantes can analyse the meaning of Amusa. On the analogy of "Moralismus - Amoralismus, Symmetrie - Asymmetrie or normal - anormal", "amusa" was translated into "a - musa" which would mean "against the muses". But there has been no word like "musa" in German. Muse is nothing but "muse". It is not "musa". Someone had forcibly interpreted "musa is muse". This must be the only one origin of several kinds of interpretations.

Johann Sebastian wrote in that letter to his old friend Georg Erdmann;
"Should Your Honor know or find a suitable post in your city for an old and faithful servant, I beg you most humbly to put in a most gracious word of recommendation for me--I shall not fail to do my best to give satisfaction and justify your most gracious intercession in my behalf."
Johann Sebastian seemed to be looking for a new suitable job. I do not know if he really meant it. Anyway Mr. Georg Erdmann took his friend's word seriously. Danzig of now is prosperous and people there need the concord music. And there is a beautiful church, St Mary's Church of Danzig.

I guessed;

He tried to talk about the job opening of Cantor or Music Director of the city with some of the city authority showing Bach's letter to them. One of the authority members said, "The statement in the letter 'The musical interests of Prince Leopold had become somewhat lukewarm, especially as the new Princess seemed to be pleasant, ..... so J. S. Bach left Cöthen for Leipzig.' does not easily make sence. I can imagine that Prince fell deeply in love with Princess. But this will make J. S. Bach lose face. It is as if he were jealous of Prince's marriage."
He added another point, "The expression 'eine Amusante' is a mishmash of German and French. In this letter there is only one French word, Amusante, here. We do not jumble them up together. If we write something in German, we write it in German. If we write something in French, we write it all in French. J. S. Bach is said to be the embodiment of the German spirit. So he should not have done this kind of a mishmash in his letter. Can you make a small revision in this letter?"
Mr. Georg Erdmann went back to the Embassy and asked one of his colleagues who was a technician of espionage to alter or delete the word 'Amusante'. The technician told that it was easy to delete the word but the part would be unnatural. He recommended to alter the word to 'Amusa'. Mr. Erdmann didn't know the meaning of this new word 'Amusa'. The technician told him not to worry, pointing that Amusa' looked like 'a-Muse' which means anti-music. "The statement of 'The musical interests of Prince Leopold had become somewhat lukewarm, especially as the new Princess seemed to dislike music, ..... so J. S. Bach left Cöthen for Leipzig.' now makes sense." So he deleted 'nte' skillfully. There remained no trace of falsification. From then on, Princess Frederica Henrietta was an infamous "eine Amusa" named by J. S. Bach.

Of course I think Mr. Erdmann didn't mean any harm to Princess Frederica Henrietta von Anhalt-Bernburg. But her happy years were too short. I can not help pitying the poor Princess. I think I should restore not only her honor but also my friend's innocence to this matter.